Process and apparatus for the con



Aug. 1, 1939. c. cou'roR 1 Re. 21,168 PROCESS AND APPARATUS FOR THE CONTINUOUS EXTRACTION OR TREATMENT OF LIQUIDS Original Filed May 14, 1954 2 Sheets-Sheet 1 .i ,N E ,.S .5

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Aug.v l, 1939. c. coUToR PROCESS AND APPARATUS FOR THE CONTINUOUS EXTRACTION OR TREATMENT OF LIQUIDS Original Filed May 14, 1934 2 Sheets-Sheet 2 Rei-med Aug. 1, 1939 PATENT OFFICE PROCESS A ND APPARATUS FOR. THE CON- TINUOUS EXTRACTION 0R TREATMENT 0F LIQUIns Charles Coutor, Premery, France, assignor to Socit Etablissements Lambiotte Freres, Premery (Nievre Department), France Original No. 2,036,924, dated April '7, 1936, Serial No. 725,630, May 14, 1934. Application for reissue March 17, 1938, Serial No. 196,576. France May 19, 1933 18 Claims.

It is a common practice in industry to extract a. deiinite body from a mixture constituting a liquid phase by a solvent or a reagent also liquid and non-miscible or incompletely'misciblc with the mixture under consideration.

For that purpose, use is generally made of columns of the 'counter-current type, with or without an inner lining, or a series of mixers provided with mechanical stirrers, followed by4 decanting apparatus; according to certain processes, the whole or' a portion of the vapours of the solvent is used, incolumns, for mixing or moving the liquids.

All these apparatus used have the inconvenience of being either of insufiicient eiiiciency, or diflicult to carry into practice, and are costly.

The present invention has for its object a process which makes it possible to eiect, continuously, and by a single passage through a simple and compact'apparatus, the methodical and complete extraction or treatment of a liquid by another liquid acting'as solvent or reagent.

The process according to lthe invention is mainly characterized by the fact that the circulation and separation of the various products:

mixture to be treated, solvent or reagent, intermediate and final products, are automatically ensured byv centrifugal force, which is used, for that purpose, under the following conditions:

(a) The liquids are caused to circulate on the counter-current principle, for example, in a multi-stage apparatus,for ensuring a methodical and complete exhaustion of the mixture.

(b) Both liquids (solvent or. reagent and mixture) are simultaneously caused to enter through fixed pipes, and they are simultaneously prof jected on conical walls rotating at a high speed. (c) Preferably, use is made, concurrently with the movable walls, of iixed surfaces arranged very near the latter, so as to produce, by friction, a thorough stirring and intimate mixing I of the liquids; this result can also be obtained by atomization, for instance, under the action of the available pressure of the liquids.

(d) The centrifugal force produces the separation lof the emulsiiied mixture into concentric layers of different densities, viz.:, into a layer comprising the solvent or reagent loaded with the body to be extracted, and into another layer formed by the empoverished mixture.

(e) 'I'he liquids of these various layers are separately drawn oii by scoop-pipes similar to those of centrifugal apparatus of the so-called cream separator type, these scoop pipes conveying the various products as stated, that is to say on the counter-current principle and through several stages in which the above operations are repeated.

When these operations are terminated, the solvent or reagent and the body it has carried along are separated by any suitable process, for instance by distillation, or again by a treatment according to a process similar to that indicated above.

Of course, for carrying out the process the principle of which has just been set forth, it is possible to provide any suitablev arrangements, capable of varying in the widest limits,` according to the conditions of application (nature of the products to be treated, of the operations to be effected, etc.) Without departing thereby from' Afrom its aqueous solutions, extraction of acetic acid from tars by washing with Water, extraction of ethyl and methyl alcohols from their mixtures with ethers, separation of the anhydrideacetic acid mixture by petroleum, extraction of phenols, extraction of essential oils, acid or alkali treatments oi petroleum on the counter-current principle, puriiication of oils and greases by oxidation 4or reduction, etc.

Likewise, any suitable plant can be devised for carrying this process into practice and especially any suitable modifications, considering the particular conditions of application, can be made in the dimensions oi the apparatus, arrangement of the scoop-pipes,'number of stages or of successive treatments, etc.

In certain cases it may be desirable or possible, considering the complexity of the mixture, to discern more than two concentric layers capable of being simultaneously separated; additional scoop-pipes and partitions can then be provided and suitably arranged.

Concerning that point, one may be led to draw oil, in the form of sludge, a precipitate lthe density of which will be comprised between those oi' both liquids.

Likewise, it is possible to use as reagent a pulverulent product which practically behaves as a liquid in the various partitions of the appadlt ratus, but, in this case, the scoop-pipes and mixing devices will koi! course be modifled. This will be done when a liquid is treated by a-carbon o decolouring earth, for instance.

Furthermore, use can be made, without departing from the invention, of a centrifugal apparatus rotating about' an axis of orientation, the liquids can be introduced insaid apparatus after previous cooling or reheating,` and, consequently, the apparatus can be heat insulated or heated, the operation can be effected in 'presence of any gas, under vacuum or under pressure, etc.

By way of example, and in order that the-in- -V vention may be more clearly understood, `a form of construction of such an apparatus will be de.,

' scribed hereinafter with reference to the accompanying drawings, this apparatus being" adapted toY be used for the extraction `of a Abody dissolved in water, by means of a light solvent.

Fig. 1 is an axial vertical section of the entire apparatus.

Fig. 1l is a cross section made according to broken line V-V of Fig, 1. Y

Fig. 1b is a partial section, on an yenlarged scale, made according to line Z-Z of Fig. 1.

Figure 2 is a similar partial view of a modtightness.

The shaft contains the inlet and outlet conduits for the products, viz.: a conduit 6 through which is admitted the mixture to. be treated and a conduit 'I through which is admitted the solvent or reagent, a conduit 8 through which is discharged the exhausted mixture, and a conduit 9 through which is discharged the solvent or reagent loaded with the extracted product. The arrows in full 4lines indicate the mixture to be vtreated and the arrows in broken lines, the solvent or reagent.

The body lis divided into six juxtaposed compartments C102 Cs by five annular partitions NiNz N5, and in each of these-compartments are arranged two other annular partitions L1M1, -IaMz LsMs, respectively; the partitions M1 to Ms have an outer diameter smaller than the inner diameter of the body I and the partitions .L1 to La have a diameter smaller than that of the partitions M1 to Ms. These partitions are arranged as follows:

The partition M1 M6 (each partition bears indicia of the compartment to the left of which it is located in Fig. 1) is arranged at right angles Vto the axis 'of the turbine, so that 4a. passageway .f ms is provided between its outer edge and thewall of the body I.

To'. the right of the preceding partition M1 Ms is a partition L1 Ishaving a central frustum-shaped portion and the outer` edge of wmchis offset relatively t6 that o? M1 Ms, so as to provide a second peripheral `passageway l1 ls.

Finally, to the left of each of the partitions M1...Ms,isathirdpartitionN1...Nsse

. cured to the inner wall of `the body I.

Free narrow vspaces D1 Ds exist between tl.: partitions L, M and other narrow spaces E1 ll. N.

. Es are provided -between the partitionsA The decanting compartments alone are-relatively large. I

The circulation of the products takes place moreover through fixed tubes, `arranged in the opens in the space comprised between the two partitions M, N and having an extension constituted by a conduit Oz, O3 On terminating in an annular jet bz be opening very near the -frustum-shaped portion of the correspondingv wall 1a .Y 1s.

On theyother hand, the solvent or reagent flows through thecompartments C;

es, c4, c: which extend from the compartment bearing the same indicia and leads to the annular jet b bearing a lower indicia.

The inlet ends ofthe scoop-pipes are so arranged that the liquids enter therein by inertia.

- The conduit 5 through which is admitted the solution terminates ina conduit O1 and an annular jet b1 opening in proximityto the vwall L1 and to which leads the scoop-pipe cz; the ends of these pipes extend through a relatively important arc'of the circumference of the apparatusI as diagrammatically indicated in Fig. 1u. 'I'he distance separating the xed and movable surfaces is so adjusted as to ensure satisfactory emulsion ofthe solution and solvent.

The discharge conduit 9 for the extracted product is fed by a scoop-pipe c1 opening in the compartment C1.

The inlet conduit I for the solvent or reagent opens in the last annular jet bu.

Finally, the discharge conduit 8 for the exhausted solution extends down, in the compartment Cs, beyond the last partition Ls.

The operation is as follows: l

The solution to be treated, admittedthrough l and O1, is projected by the jet b1 on the frustumshaped portion of the wall L1, at the same time as the solvent or reagent which'has already passed through the ve compartments Cs Cz and f is led to this .iet b1 by the scoop-pipe cz.

Both liquids, intimately mixed, thus enter the mixing space orchamber D1 in which the exhaustion of the solution begins.

These liquids are subjected to the action of centrifugal force and,'owing to their difference of density and of their non-miscibility, they separate and form two concentric annular layers P1, Pz, the outer layer P1 being formed by the solution, which is the heavier, and the inner layer Pn by the solvent.

The separating surface X-'X of the two layers reachesfrduring fthe rotation, a level which depends on the radial distance separating the inlet ends of the scoop pipes c1 and f1, c: and fz, etc., and on the density of the liquids treated, and this radial distance is so adjusted that in each compartment the said surface of separation XX is located'at a distance from the axis of rotation at most equal to the radius of the respective disc L1 or Le and however large enough in order that the layer of solvent comprised between 'the `level XX and the level YY of the inlet ends of the solvent scoop-pipes c1cz" should have a sufficient thickness. v

The solvent of the layer Pz is drawn oil' through the scoop-pipe c1 and discharged through the conduit 9, whilst the solution, passing through m1 and E1 is drawn olf through the 'jet f1 and sent,

C1 from left,Y A to right on the drawings through scoop pipes cs,

through Oz, bz, into the compartment C2, at the same timel as the solvent coming from the compartment C: passes through the scoop-pipe c3.

j`The exhaustion thus progressively proceeds in two concentric oriiiceszthe inner jet serves for,

the admission of the solution, which is sent to it from one compartment by a scoop-pipe f, and the outer jet c', serves for the admission of the solvent, which is sent to it from the next compartment through a scoop-pipe c" I claim: 1. An apparatus for removing atleast one of 'the constituents from a liquid mixture by centrifugation of the mixture and scooping the separate liquid layers, comprising a drum rotatively mounted and laterally bounded by two annular discs, arrangedfor forming with the drum an inner annular compartment, means for causing this drum to rotate at a high speed, -two annular discs secured within this drum and arranged for dividing said annular compartment into a lateral space of great width, a narrow intermediate space' and a narrow lateral space, the disc limiting the narrow lateral space extending outwardly to a small distance from the periphery of the drum, and the disc separating the intermediate space from the space of great width extending outwardly to a greater distance from the periphery of said drum, a xed nozzle opening at the inner periphery of said drum,

`in the intermediate space and directed towards the constituent to be removed from the mixture,

and a scoop-pipe extending from the narrow lateralV space and adapted to evacuate the treated and exhausted mixture.

2. An apparatus for removing at least one of the constituents from a liquid mixture as claimed in claim 1, in which the inner peripheral portion of the disc separating the intermediate space from the spacev of great width, hasa portion in the shape of a conical surface.

3. An apparatus forvremoving at least one of the constituents from a liquid mixture, as claimed 'in claim 1, in .which the outlet orifice of said nozzle opens against the portion in the shape of a conical surfacey separating the intermediate space from the space of,v great width, said oriiice being very close to`said conical surface.

4f. An apparatus for removing at least one of -the constituents from a liquid mixture, as claimed in claim l, in which the end of the scoop-pipe extending from the lateral spaceof great width and the end of the scoop-pipe extendingl from theV narrow lateral space, are directed in a direction reverse to the direction `of rotation of the drum.

5. An apparatus operating on the countercurrent principle for removing at least one of the constituents from a liquid mixture as claimed in claim l, in which the drum is internally divided into a series of annular compartments,

each of which is divided into a lateral space of great width, a narrow intermediate space and a narrow lateral space, and has a nozzle within each intermediate space, the piping adapted to convey the mixture of liquids to be treated opening in the last nozzle at one of the ends'of the drum, the piping adapted to convey the solvent opening in the last nozzle at the other end of the drum, the narrow lateral space of each compartment being connected to the nozzle of the foilowing compartment, relatively to the direction of circulation of the mixture being treated, by a scoop-pipe, and the space of great width of each compartment being connected to the nozzle of the following compartment, relatively to the direction of circulation of the solvent, by another scoop-pipe.

6. A method f or extracting a body from a complex liquid mixture by means of an auxiliary body acting as solvent or reagent on said body to be extracted, thishauxiliary body being liquid and nonmiscible with the liquid mixture to be treated, said method consisting in introducing together the liquid mixture to be' treated and the auxiliarybodyintoa rotary vessel where they come in intimate contact, then separate in the form of concentric layers under the iniluence of centrifugal force, one of the layers being especially constituted by the auxiliary body and that of the liquid bodies it has dissolved, and the other layer being especially constituted by the impoverished liquid mixture, and in continuously extracting from each or" 'these layers the portion situated nearest the axis of rotation by a scooping operation.

7. A method for extracting a body from a complex liquid mixture by means of an auxiliary body acting as solvent or reagent on said body to be extracted, this auxiliary body being liquid and nonmiscible with the liquid mixture to vbe treated, said method consisting in introducing together the liquid mixture to be treated and the auxiliary body into a rotary lchamber where they come in intimate contact,` then separate in the form of concentric layers under the iniiuence of centrifugal force, one of the layers being especially constituted by the auxiliary body and that of the liquid bodies it has dissolved, and the other layer being especially constituted by the impoverished liquid mixture, in continuously extracting from each of these layers the portion situated nearest the axis of rotation by a scooping operation, and in discharging. the liquids thus extracted respectively in two other rotary chambers Where they again separate in the form of concentric layers and so on, so that the solution circulates in one direction and is consequently enriched with the body to be extracted, and the impoverished liquid mixture insoluble in the auxiliary body circulates in the reverse direction and is consequently purifled, the evacuation and transfer of the liquids from one chamber to another being always produced by scooping out from portions of said liquid layers situated the nearest to the axis of rotation.

8. In'a process of treating one liquid substance with another liquid substance of different density containing a solvent or reagent for a part of the first liquid substance, lthe steps of centrifugally stratifyingsaid liquid substances in concentric layers about an axis, causing said layers while subject to centrifugal force to flow beside one another in a direction transverse to vsaid axis.

'Iii

parallel to the axis, and continuously scooping both liquid substances by their force of rotation from said separated portions.

9. In a process of treating one liquid substance with another liquid substance of different density containing a solvent or reagent for a part of the iirst liquid substance, the steps of centrifugally stratifying said liquid substances in concentric layers about an axis, causing said layers while subject to centrifugal force to iiow beside one another in a direction transverse to said axis against the actionv of centrifugal force in separated,l non-contacting portions each having its surface ,nearest said axis free and substantially parallel to the axis, continuously scooping both liquid substances by their force of rotation from said separated portions, and repeatedly subjecting said scooped layers in counter-current with one another after commingling them with one another to such centrifugal and scooping operations.

10. In a process -of treating one liquid substance with another liquid substance of different density containing a solvent or reagent for a part of the first liquid substance, the steps of causing a continuous iiow of said liquids in counter-current to one another through a centrifugal machine having several annular compartments, in each compartment centrifugally stratifying said liquid substances in concentric layers about an axis, causing said layers while subject to centrifugal force to flow beside oneanother in a direction transverse to .said axis against the action of centrifugal force in separate, non-contacting portions each having its surface nearest said axis free and substantially parallel `to the axis, continuously scooping both liquid substances by their force of rotation from the free surfaces thereof ineach compartment, and repeatedly leading said scooped layers in counter-current to one another from compartment to compartment by their force of rotation.

, ll. In a process of treating one liquid substance with another liquid substance of ditl'erent density containing'a solvent or reagent for a part of the rst'liquid'substance, the steps of causing a continuous flow of said liquids in counter-current to one another through a centrifugal machine having several annularV compartments, in each compartment centrifugally stratifying said liquid substances in concentric layers about an axis, causing said layers while subject to centrifugal force to ow beside one another in a direction transverse to said axis against the action of centrifugal force in separate, non,- contacting portions each having its surface nearest said axis free and substantially parallel to the axis, continuously scooping both liquid substances by tneir force of rotation from the free surfaces thereof in each compartment, repeatedly leading said scooped layers in counter-current to one another from compartment to compartment by their force of rotation, and finally scooping one repeatedly treated liquid from the rst compartment and the other repeatedly treated liquid from the last compartment.

12. In a process of treating liquid hydrocarbons with acids, the steps of causing a continuous flowA of said hydrocarbons and acids m counter-current to another through a centrifugal machine having several annular compartments, in each compartment centrifugally stratifying said hydrocarbons Yand acids'in concentric layers about an axis, causing said layers while subject to centrifugal force to.ow beside one another ina action of centrifugal force in separated, noncontacting portions each having its surface nearest said axis free and substantially parallel to the axis, continuously scooping said hydrocar.- bons and acids by their` force of rotation from said separated portions, and repeatedly leading said scooped hydrocarbons and acids in countercurrent to one another from compartment to compartment by their force of rotation.

13. In a process of treating liquid hydrocarbons with alkalies, the steps of causing a continuous flow of said hydrocarbons and alkalies in countercurrent to one another through a centrifugal machine having several annular compartments, in each compartment centrifugally stratifying said hydrocarbons and alkalies in concentric layers about an axis, causing said layers while subject to centrifugal force to flow beside one another in a direction transverse to said axis against the action of centrifugal force in separated, non-contacting portions each having its surface nearest said axis free and substantially parallel to the axis, continuously scooping said hydrocarbons and alkalies by their force of rotation from said separated portions, and repeatedly leading said scooped hydrocarbons and alkalies in counter-current to one another from compartment to compartment by their force of rotation.

14. In a process of treating one liquid substance with another liquid substance of different density containing a solvent or reagent for apart of the first liquid substance, the steps of centrifugally stratifying said liquid substances about an axis in concentric layers separated by an intermingled y layer, continuously leading further liquid sub-V stances into the interminglcd layer between said concentric layers, and causing said separated layers while subject to centrifugal force by their difference in specific gravity to flow separated by walls beside one another in a direction transverse to said axis, each separated layer having `its surface nearest said axis free and substantially parallel to said axis, and continuously scooping each separated layer by its force of rotation.

15. In a centrifugal separator, a compartment mounted to rotate about an axis and having its portion remote from the axis closed, a partition in said compartment transverse to said axis dividing the compartment into two sections and providing a passage between said sections adjacent the outside of the compartment, and means toV feed a mixture of liquids into one of said sections at a point closer to the axis than said passage but further from the axis than the inner edge of said partition, and means to scoop liquid from each of said sections in the portion adjacent said axis.

16. In a centrifugal separator, a compartment mounted to rotate about an axis and havingits portion remote from the axis closed, a pair of partitions in said compartment dividing the same into sections and extending transversely to the said axis, the first of said partitions providing a passage between two of said sections adjacent the outside of the compartment, the second partition terminating closer to the axis of the shaft than the innermost point of said passage, means to feed a mixture of liquids to the section between said partitions, and means to scoop liquid from each of the outer. sections in the portion adjacent said axis. v A f 1'1. In acentrifugal separator, a compartment mounted to rotate about an axis and having its portion remote from the axis closed, a pair of partitions in said compartment dividing the same into direction transverse to said axis against thev feed a mixture of liquids to a. section on one side ofsaid second partition, and means to scoop liquid from each oi the other two sections in the portion adjacent said' axis.

18.' A centrifugal separator comprising a series of compartments mounted side by side for rotantion about an axis, each compartment having its portion remote from the axis closed,`a partition in said compartment transverse to said axis dividing the compartment into two sections and providing a passage between said sections adjacent the outside of the compartment, means to scoop liquid from each of said sections in the portion adjacent said axis, means to mix the liquid scooped from the second section of each compartment except the last of the series with the liquid scooped from the ilrst compartment of the seconcl/l succeeding compartment of t he series, means for mixing the' liquid scooped from the second section of the next to last compartment and from the ilrst section of the second compartment of the series withvfresh liquid, means for introducing such mixed liquids into the intermediate sections at points closer to the axis than said passages but further from the axis than the inner edges of said partitions, and means to remove liquids scooped fromthe ilrst section oi the rst compartment and the second section of the last compartment.

CHARLES COUTOR. 

